At it's core, life is frequently unfairly treated. I've seen the argument: If life is about living, why should it have any killing mechanisms? And that argument is partially true, it shouldn't have some fear-inspiring global death mechanic. (Extinction: deal 3 damage to all creatures, survivors have their ability replaced by mitosis)
But by that same coin, Death is about killing, why is it allowed to have creatures?
I understand the argument that there should be punishment for trying to harm life's creatures, but if we're drawing on the real world, there are none. If you find a pond and smash a frog, nothing bad will happen to you. The other frogs in the pond won't attack. The same holds true for every creature in currently in the element of life, actually.
Some sort of pride based mechanic would be cool. For instance: Bear. If a creature would die, all other bears get buffed. This won't work for 2 reasons:
1. It is unreasonable that you would get out multiple bears before the enemy kills it.
2. It is unreasonable that an enemy would kill your bear once you have multiple out.
If your bear is strong enough to survive CC (which currently requires 4-6 HP), than it's too slow to rush. And as life has no draw power, it is unlikely to get more than 2 bears out before the game is over.
At it's core, the card is flawed because it relies on your opponent's mistake, not your own good play.
So how DOES life survive in the real world.
Life creatures don't protect each other. If a creature lights on fire, that's it, bye. If wolves attack a tribe of buffalo, the buffalo all run together, and the slow sick buffalo gets eaten. Yes, a mother will attack you if you threaten it's cubs, but I listed earlier why this method wouldn't be smart. Life /does/ survive because it generates more creatures that can be killed.
And you say, "that's what mitosis is". I won't take credit for designing mitosis. I did come up with bunnies, which ran off of a similar mechanic. The card was underpowered and it's probably a good idea it wasn't added, but there's a reason I made mitosis a creature's ability and not a spell. If you put mitosis on a creature, and every time you activated the ability you got another creature with mitosis, there would be durability and creature protection. More creatures than can be controlled. Right now, playing mitosis on a creature is basically condemning it.
Here's an example of a durable CC resistant life card.
Evolution Beast 5 life
1|1, 1|3 upgraded.
This creature has the passive: Mutant.
3 entropy: Create a copy of this evolution beast. It will randomly get between -2/-1 and +3/+3. You can activate this ability multiple times per turn, and on the first turn the card is played.